Journal box end thrust construction



March 16, 1954 w. HOLIN JOURNAL BOX END THRUST CONSTRUCTION Filed July 8 1950 .Uvvmvroe Patented Mar. 16, 1954 JOURNAL BOX END THRUST CONSTRUCTION William Holin, Riverside, Ill., assignor to General Motors Corporation, Detroit, Mich., a. corporation of Delaware Application July 8, 1950, Serial No. 172,769

8 Claims. (01. 308-41) This invention relates to railroad journal boxes and particularly to an end thrust arrangement for use in a journal box.

An object of the invention is to provide an improved thrust construction for journal boxes and especially an antifriction thrust arrangement which can be installed in an end cap of the journal box.

A further object is to provide an improved adjustable cushioned thrust arrangement for journal boxes and which can be assembled under a preload in the end cap of the journal box.

To these ends and also to improve generally upon devices of this character, my invention consists in the various matters hereinafter described and claimed. In its broader aspects, the invention is not necessarily limited to the specific structures selected for illustrative purposes in the accompanying drawings wherein Figure 1 is a longitudinal section at the outer or front end of a journal box and taken along the lines 3-4 of Figure 4;

Figure 2 is a cross section through one form of my annular cushion member;

Figure 3 is a fragmentary section showing one form of my cushion and thrust block assembly;

Figure 4. is a fragmentary end view of the end cap and thrust block;

Figure 5 is a sectional view taken similar to the section of Figure l and showing another form of my thrust block and cushion assembled in the end cap; and

Figure 6 is a sectional view showing the thrust block and cushion member used in Figure 5.

The end portion of an axle 2 is provided with a pressed-on inner raceway sleeve t journalled for rotation in roller bearings 5 arranged to roll against an outer raceway sleeve 3 mounted in a journal box it. The journal box construction may have various forms but is preferably similar to that illustrated in the United States Patent No. 2,483,922 to Brittain and includes a ring I? which collects lubricant from the bearings and delivers it to a thrust unit. The outer end of the journal box has a radially inwardly projecting end flange It defining a round opening it which receives an interrupted cylindrical flange 2E3 axially projecting from an end cap 22, the flange 25} being interrupted by gaps or slots 23. A thrust block '25 loosely fits within the flange 2a with some clearance 'andfhas aseries of outwardly prbjecting'lugs 2t loosely entering the slots 23 to hold the thrust .blochfrom rotation.

A portion of each lug 23 extends into a recess 28 .in the end cap 22. The end cap 22 has an outwardly extending flange 35 which is secured as by bolts or can screws 3! to the journal box, suitable shims 82 being imposed between the flange so and the flange I l. The end cap has a circular recess 33 defined in part by a cylindrical wall 3% which is a continuation of the bore of the flange 2c, the wall 3 meeting a short con-' ical wall as which in turn meets a flat bottom wall 31. This fiat bottom wall also meets a short conical wall 33 that joins an annular projection 48' extending from the center of the end cap and loosely fitting part way into a central bore through the thrust block 24.

An annular pad or cushion d2, composed of an inherently resilient material as synthetic rubber or the like, is centered by the conical faces 36 and 38 and has a substantially rectangular cross section when mounted under a normal preload. When uncompressed, as shown in Figure 2, this resilient cushion t2 has a flat end face 43 and a convened end face is forming an annularly extending bulge. As illustrated in Figure 1, this cushion d2 under preload has its convexed face i l deformed fiat against a fiat end face 35 of the thrust block 25. The thrust block 2 1. is held against the cushion 32 by a split ring d5 demountably sprung into an annular groove in the flange 26, this ring engaging a thrust block shoulder ll and surrounding a thrust blocl: projection it whose flat end face it is intermittently engaged by the axle 2 when it shifts endwise in its bearings. To facilitate removal, the ends of the split ring it are preferably located in one of the slots 23 in the flange 253. Under a heavy thrust load, the thrust block it will shift deeper into the recess is in the end cap further com pressing the resilient cushion t2; and if this thrust load is sufficiently heavy, the resilient cushion will deform and fill the decreasing space and finally go solid before the lugs 25 bottom in I the recesses 23.

The thrust block as is non-metallic and preferably made from a resinous wear-resistant material which has a very low coeificient of friction against steel in the presence of lubricant; one satisfactory material being known as Gatke' and composed of graphite-coated fibers or of graphite-coated fabric layers which are impregmated with a phenolformaldehyde resin that is heat-set in a suitable mold. This material at tracts oil which adheresto it tenaciously and provides adequate lubrication which is especiallyimportant for this type of construction wherein the thrust face operates in a vertical plane. This Gatlze material will not score the axle. Thrust blocks of bronze and other material as previously used may cause scoring and require the facing off of the end of the axle which then has the further disadvantage of requiring adjustment of the spacing between the axle and the thrust block. By employing this non-axle scoring block, it is unnecessary to provide any adjusting mechanism for taking up wear at more or less frequent intervals. The clearance between the Gatke thrust block and the axle can be initially set larger than the normal clearance to give the apparatus opportunity to run in after which one or more of the shims 32 can be removed to reduce the running clearance to normal.

Figure 3 shows a slightly difierent embodiment wherein a resilient cushion 42A, similar to the cushion 42, has its flat end face 43A secured as by rubber cement or other suitable cement to the flat face 55 of the thrust block 24. This thrust block and cushion arrangement replaces the thrust block and cushion of Figure 1, and the convexed cushion face 44A deforms to flat seating engagement against the end cap face 3? under normal preload.

Figures 5 and 6 show another embodiment wherein a resilient cushion 52B, generally similar to the cushion 42, has its flat end face 433 secured as by rubber cement or other suitable cement to a flat washer 52 of metal, flber plastic or other suitable rigid material. The inner di ameter of this washer preferably is less than that of the annular cushion 42B and the outer washer diameter preferably exceeds that of this annular cushion to provide better support for the cushion under load. When assembled under preload, a flat face 54 of the washer 52 engages the flat face 45 of the thrust block 24 and the convexed face 443 of the cushion is deformed into flat seating engagement with the end cap face 3?. The thrust block and the cushion 42B are held under preload by the split ring 45 in the same manner as previously described.

In each embodiment, the end cap, thrust block, annular cushion and split ring provide a preloaded cushioning unit composed of few parts. Under heavy load, the cushion will resiliently deform and finally completely fill the decreasing recess 33 in the end cap thereby limiting the extent of end thrust of the axle. This unit-handling end cap assembly can b readily bolted to or axially removed from the box without affecting the preload and this preload will have no effect on the bolting operation.

I claim:

1. A preloaded thrust unit for journal boxes comprising an end cap having an annular recess and an inwardly axially projecting annular flange, said flange being provided at its inner end with a gap, a thrust block entering within the projecting flange and having a lug entering said gap, a compressed resilient annular cushion within and coaxially of said recess between the thrust block and the end cap, and a split ring demountably secured to said projecting flange and engaging the thrust block to hold the cushion under compression.

2. A preloaded thrust unit for journal boxes comprising an end cap having an annular recess surrounding a central projection, an annular cushion in the recess and surroundin said projection, a one piece thrust block of wear-resistant resinous material carried by the end cap and slidably fitted over the central end cap projection, the cushion being compressed between the thrust block and said end cap, and a demountable snap ring carried by the end cap and engaging the thrust block to hold all of said parts together as a unit.

3. In a device of the character indicated, an axle, a journal box, an end cap secured to the journal box and having an internal annular recess surrounding a central end cap projection, a thrust block in the end cap and surrounding the end cap projection, an annular cushion mounted in the recess in surrounding relation to said end cap projection and compressed between the thrust block and the end cap, the thrust block having a thrust face engageable with and normally spaced from the end of the axle, means mounted on the end cap to adjust the spacing between the thrust block and the axle, and a member demountably secured to the end cap and holding the thrust block, cushion and end cap together as a unit with said cushion under predetermined initial compression.

4. A preloaded thrust unit for journal boxes comprisin an end cap containing an annular recess, an end cap projection within and substantially central of said recess, an annular thrust block of molded resinous material mounted for axial movement in said recess, a resilient annular cushion extending between the thrust block and the end cap, end cap means positioning the cushion in radially spaced relation to the peripheral wall of the recess and to said end cap projection, said cushion being resiliently deformable in all directions, and a ring demountably received in the end cap and engaging the thrust block to maintain the cushion under a predetermined initial compression.

5. A preloaded thrust unit for journal boxes comprising an end cap having an annular recess surrounding an axial projection, an annular thrust block surrounding the axial projection, a resiliently deformable annular cushion in said recess and substantially coaxial of the thrust block, said cushion being compressed between the thrust block and the end cap and having opposed faces one of which has an annularly extending bulge when the cushion is uncompressed, and a member demountably securing the thrust block within the end cap with the cushion compressed a predetermined extent therebetween.

6. A preloaded journal box thrust construction comprisin an end cap having an annularly extending flange projecting axially into the journal box, said flange being interrupted at its end by circumferentially spaced openings, the thrust block slidably fitting within the projecting flange and having circumferentially spaced radially extending lugs respectively entering said openings. a resilient annular cushion compressed between the thrust block and the end cap, said flange having a radially inwardly extendin groove adjacent the open end of the flange, a split ring projecting radially inwardly from the groove and engaging the thrust block to demountably hold the thrust block within said flange and hold the resilient cushion under axial compression, and the ends of the split ring terminating in one of said openings.

'7. In a device of the character indicated, an end cap demountably secured to and closing the open end of a journal box, the end cap having an annular recess, an annular cushion within the recess, the cushion being resiliently deformable in all directions, an end cap portion locating the cushion substantially coaxial of the recess and radially spaced from the peripheral wall of said recess, a thrust block supported by the end cap for axially slidable movement in said recess, the thrust block being integrally secured to the cushion, and a thrust block engaging member demountably secured to the end cap and locating the thrust block against the resilient cushion to maintain the cushion under a predetermined initial compression.

8. A preloaded thrust unit for a journal box comprising an end cap having an annular recess, an annular cushion of resilient material in the recess, a washer secured to and in unit handling relation with the cushion, an axially extending end cap projection surrounded by said recess, an annular thrust block slidably mounted for movement in the end cap and guided in its movement by said projection, the thrust block being engageable with said washer under pressure to compress the cushion, and a thrust block engaging member demountably secured to the end cap and demountably maintainin the thrust block under an initial predetermined pressure against the washer.

WILLIAM HOLIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 402,987 Sharpneck May 7, 1889 2,141,122 Boden Dec. 20, 1938 2,251,126 Gatke July 29, 1941 2,273,308 Young Feb. 17, 1942 2,317,920 Landt Apr. 27, 1943 2,533,917 Buckius Dec. 12, 1950 FOREIGN PATENTS Number Country Date 839,034 France Mar. 22, 1939 

